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Some nine months ago in the London suburb of Eltham a new multiplex opened in the middle of the high street. This cinema was several years in the building (an entire year necessary for the safe demolition of the previous building) and was constructed to a very high standard. Walls are massive poured concrete, the external architecture most appealing. Sound is Atmos and projection Sony in all screens. On opening presentation was to a very high standard indeed! First class sound (some of the best I have experienced) and picture. Nine months on and matters have deteriorated in one area. The sound remains superb. Front of house staff could not be bettered. The projected images however show artifacts immediately obvious to anyone who understands these things. In one screen, diffuse shadow areas are very visible in several locations. In another areas of false colour cast persist. I was very surprised that projectors less than one year old would suffer such problems. I know DLP chips are not used in these projectors, I have two such machines both about 9 years old which are artifact free. Is this a typical issue with liquid crystal imaging chips and can it be corrected using an updated colour map done every so often? Really quite disappointing that projectors should degrade so rapidly. If it is possibly laser light sources would postpone this.
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Here is a simple rule...if a device moves air (fans), it also moves dirt. The trick in filters is to allow enough air through to do the cooling while stopping the contaminates. It is difficult and all fail, to a degree. NEC has some of the better filters and popcorn oil came right on through as a liquid and the internal fan blew it right on the DMD. The liquid looked almost like iced tea.
I'm seeing degrading in projectors in general. Dirt in the light path causing uneven light and, in some cases, significantly less light. I recently encountered where the plating on the heat sink around the light pipe had degraded so it wasn't shiny anymore...this allowed all of the heat to absorb there rather than be reflected away and the light pipe heated up as a result.
Stuck pixels are becoming more of a thing (both on and off). At the cost of repairing a light engine (not to mention being down while the lengthy repair takes place), I'm sure some exhibitors are rationalizing just "how bad" things are before they fork over a large sum of money. Note, in the USA, Strong will RX NEC prisms, if you have one that needs attention so there is no down time. -
Cooling is a challenge! Forced air cooling turns the equipment into a vacuum cleaner filter. Years ago, high power broadcast transmitters were water cooled. There was a cooling pond outside the transmitter building. Plastic pipe carried distilled water at ground potential up to the tube plate at several thousand volts above ground. Transmitters then went to forced air cooling, and it was a pain to keep them clean. Now, most transmitters are solid state and liquid cooling is coming back. A heat exchanger is put outside the building. Besides keeping the transmitter clean due to the lack of forced air, the building cooling requirements are reduced since the transmitter heat is taken directly outside instead of having to be pumped out by the air conditioning. I've seen some liquid cooling on laser-based projectors. I expect this will help keep projectors clean.
Harold
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The Sonys are indeed prone to some premature color shifts - in part caused by dirt accumulation, in part caused by panel uniformity shifts. In general, this can be corrected by regular maintenance.
9 months, though, appears a little too premature to me. Maybe they run their Sonys many shows a day at very high light levels, maybe many of them in 3D mode. There are also a few tech bulletins dealing with improved air filtering and cooling schemes.
In a new bulding, I would think that there is a lot of initial dust buildup from the construction. I would assume that during the first year, the air filters would need some extra cleaning. I would approach the manager and have him arrange for a service team to show up. Should be no problem to arrange for that in the UK. The current Sonys are easy to clean.
- CarstenComment
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I have let them know. It will be interesting to see how matters improve after a thorough service visit. This may already be in place of course, lamps and filters do need changing etc. Another problem in one screen was one corner of the picture only being well out of focus. I know myself how easy that problem is to fix, so I suspect a lack of skilled maintenance. Remote management is common these days. Remote maintenance does not make sense.Comment
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But wasn't that always the case? Each manage/exhibitor had their own level of "how bad" tolerance, which much too often was based more on a quick subjective look at the screen rather taking any light meter readings. "Hey Tommy (minimum wage, high school usher), there was a complaint about the picture in #3 is too dark....go in an check it out." And of course the subjectivity, such as it was, was heavily tainted by an economic bias rather than a desire to keep up to any SMPTE screen brightness specs.I'm sure some exhibitors are rationalizing just "how bad" things are before they fork over a large sum of money.Comment
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Not so long ago I repaired a Panasonic 3 chip professional projector. This had diffuse artifacts present on bright scenes which were most distracting. As they were grey not coloured it was obvious dirt had not penitrated the spce between a DLP chip and prism. These projectors were designed for compactness (relatiive to their high light output). It took about ten hours to fully dismantle, clean all the optical surfaces and reassemble. Dozens of very frail connectors and cables to deal with. Something like 20 optical surfaces to clean with great care. Can do the same job on a film projector in 10 mins. Cured the problem though. Just wished maintainability was higher on the projectors design engineers agenda!Comment
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I'd say that most Barco projectors, starting at Series 2 are pretty well maintainable and pretty modular in most aspects. Some stuff is so tightly integrated, it's pretty hard to make it absolutely modular, especially since it still needs to fit in limited real-estate.
It's hard to keep the crud out of your machines. Even machines using water-cooling still tend to end up with some buildup of crud inside their so-called sealed compartments. Also, water-cooling itself can build-up crud inside the ducting and heat exchangers.
Regarding the original topic: It's pretty odd to see 9-month old Sony projectors requiring a uniformity/gamma calibration, especially if this affects multiple rooms. Some early generation SRDX machines were known to get into trouble after a certain number of hours. Maybe the machines were underspeced and are pushing at their maximum light output all the time?Comment
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Not that odd, the Sony requires a regular maintaining scheme, and with our system, even within a couple weeks, I can notice requirement for Uniformity corrections.
The overall image quality and contrast is at a very high level after calibration, therefore any detoriation is quickly noticed. The DLP 4k in contrast to that starts at a rather low image quality level, some setups I know offer a measured 15 to 1 contrast ratio in chequer field patterns. Therefore detoriations are not that easily noticed. Whereas I measured a 5500 to 1 ratio in chequer field with our Sony after calibration. I have to admit, choosing smallest image on screen (large image raises limiting contrast), no portglasses installed.Comment
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Which is why you're supposed to flush out the cooling circuit and refill it with fresh coolant periodically.Originally posted by Marcel Birgelen
Failures of the liquid cooling system is the #1 cause of Barco breakdown calls that I attend, and by a clear margin. These breakdowns are almost always caused by failure to do planned maintenance. With Series 1 Barcos, the usual failure is that the barb couplings between the hose and the DMD cooling blocks becomes clogged with crystallized coolant and/or hose rubber deposits. This requires digging these deposits out with a needle, pumping air through the DMD cooling block, replacing the hoses, refilling and repressurizing. With Series 2 Barcos, it's usually a pump failure, because the pump has been in use for 7-8 years (per the service manual, you're supposed to replace it after four).
The advantage of liquid cooling is that you're not blowing crap into the projector that you will with a forced air system, no matter how often you replace the filters. The disadvantage is that it is more expensive to maintain (in skilled labor - air filters can be replaced by the end user, but a coolant flushout and/or pump replacement cannot).
That having been said, I've seen NECs (especially 900s) overheat and throw a red tail light because the air filters were never replaced, too.
These things need the colors re-shooting every two weeks?! If so, I'm relieved that I don't have to service any Sony installations!Originally posted by Stefan ScholzComment
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Oh no Leo...by far, the biggest failure item I have on Barco Series 2 projectors is the signal backplane. I've had to reseat the ICP on all three OEMs of DLPs but Barco...something like 100:1 of the others (particularly as we head into the dry winter season). And then it is only a matter of time until reseating only buys you a month or so of good operation and finally, change the signal backplane. I really wish they would revisit the connectors they use and get a MUCH better connector. Heck, they even have an Info-T regarding the ICMP when really the root problem is their connectors on the signal backplane. if the problem was JUST the ICP, then I'd see similar problems (in terms of frequency) on other brands.Comment
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Interesting - I only had to replace one backplane last year (though a co-worker also did another), but four pumps. Reseating cards is a frequent need, though.Comment
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I'm probably up to 10-12 backplanes out of 200 or so units. Zero Christie or NEC backplanes. As for pumps, very few have outright died and Barco has one change them on "D" Maintenance every 4 "operational" years so that is probably why they haven't failed on us much. I don't think any have failed under the 4-year mark.
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When it comes to filters, the best thing to do is to stick to the better Heppa Filters if your manufacturer supplies that type. Yes they cost more, but light engines are also expensive. I also put thin foam tape along the edge of the filters where they seal against the projector. This has helped a lot. The worst case of popcorn oil I have ever had was in a Christie ZX that was at the top of the booth stairs.The lamphouse was litterally dripping in popcorn oil and it had to be completely dismantled and cleaned. The theater owner put in a better popper exhaust that vented outdoors after that.
MarkComment
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Maybe a little bit off the path...Originally posted by Steve Guttag View Post
Does anybody know what manufacturing class digital projectors are built to?
Class 1: General, consumer electronics.
Class 2: Industrial, heavy use equipment.
Class 3: Medical, military and mission-critical equipment.
I would expect to see DCP equipment being built to Class 2 but I would prefer Class 3.
The reason I'm asking is because you are saying that there are a lot of failures for things that sound like quality control or poor design but I also think that it could be because they are being built to a lower quality standard in order to save money... at the customer's peril and expense.
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